The present invention relates to an image processing system, projector, program, information storage medium and image processing method which can correct the distortion of an image.
An image projected from an image display device such as a projector or the like may be distorted to create a so-called keystone distortion in the vertical or horizontal direction, depending on the relationship between the image display device and a position onto which the image is projected therefrom.
Therefore, the image display device must display an image after any distortion therein has been corrected.
In general, a projector with a function of correcting the keystone distortion semi-automatically corrects the image distortion when a user indicates each of four corners in a screen using a mouse or the like.
However, it is difficult and troublesome for the user to exactly indicate the four screen corners using the mouse.
To solve such a problem, for example, Japanese Patent Laid-Open No. 2000-241874 has proposed a projector which can correct a keystone distortion in an image by detecting points on a screen, based on sensing information from a camera located in the front of the projector.
However, such a technique of correcting the keystone distortion based on the screen as disclosed in the Japanese Patent Laid-Open No. 2000-241874 can only correct the distortion in an image projected within the range of the screen, but cannot correct the image distortion if an image is projected onto a region other than the screen, such as wall.